Fabrication of yeast β-glucan/sodium alginate/γ-polyglutamic acid composite particles for hemostasis and wound healing

Particles with a porous structure can lead to quick hemostasis and provide a good matrix for cell proliferation during wound healing. Recently, many particle-based wound healing materials have been clinically applied. However, these products show good hemostatic ability but with poor wound healing ability. To solve this problem, this study fabricated APGG composite particles using yeast β-glucan (obtained from Saccharomyces cerevisiae), sodium alginate, and γ-polyglutamic acid as the starting materials. The structure of yeast β-glucan was modified with many carboxymethyl groups to obtain carboxymethylated β-glucan, which could coordinate with Ca2+ ions to form a crosslinked structure. A morphology study indicated that the APGG particles showed an irregular spheroidal structure with a low density (<0.1 g cm-3) and high porosity (>40%). An in vitro study revealed that the particles exhibited a low BCI value, low hemolysis ratio, and good cytocompatibility against L929 cells. The APGG particles could quickly stop bleeding in a mouse liver injury model and exhibited better hemostatic ability than the commercially available product Celox. Furthermore, the APGG particles could accelerate the healing of non-infected wounds, and the expression levels of CD31, α-SMA, and VEGF related to angiogenesis were significantly enhanced.

Active compounds from Calendula officinalis flowers act via PI3K and ERK signaling pathways to offer neuroprotective effects against Parkinson's disease

Calendula officinalis flowers, associated with diverse biological effects, could be utilized as functional food ingredients to play a crucial role in human health. In this study, we examined the anti-PD activity of C. officinalis flower extracts and investigated their bioactive compounds and molecular mechanisms based on LC-MS/MS assay, bioinformatic exploration and in vitro treatment of SH-SY5Y cells. C. officinalis extracts exhibited significant positive effects on the length and fluorescence density of the dopaminergic neuron region in zebrafish larvae. At 10 μg/mL, the extract restored the length to 96.54% and fluorescence density to 87.77% of the control values, which was equivalent to the effect of a positive drug, indicating the extract's powerful potential to alleviate PD symptoms. Five active compounds, including chlorogenic acid, 3,4-dicaffeoylquinic acid (DA), rutin, isorhamnetin 3-O-glucoside (IG) and calenduloside E (CE) were identified in extracts by LC-QTOF-MS/MS. Hsp90α, PI3K and ERK were revealed as core targets of DA, IG and CE in relation to anti-PD activity. The compounds docked deeply within the pocket region of Hsp90α protein, and their binding energies (∆G b) were -6.93 kcal/mol (DA), -6.51 kcal/mol (IG) and -3.03 kcal/mol (CE), respectively. Subsequently, they concurrently activated the PI3K/Akt signaling pathway and inhibited the ERK signaling pathway, thereby preventing neuronal death and alleviating neuronal degeneration. These compounds from C. officinalis could be potent nutraceutical agents with protective properties that may shield dopaminergic neurons against the damage caused by PD. Our findings provide a basis for utilizing the C. officinalis flowers in functional foods.

Neuroprotective effect of chlorogenic acid on Parkinson's disease like symptoms through boosting the autophagy in zebrafish

Parkinson's disease (PD) is characterized by both motor and non-motor symptoms, including hypokinesia, postural instability, dopaminergic (DA) neurons loss, and α-synuclein (α-syn) accumulation. A growing number of patients show negative responses towards the current therapies. Thus, preventative or disease-modifying treatment agents are worth to further research. In recent years, compounds extracted from natural sources become promising candidates to treat PD. Chlorogenic acid (CGA) is a phenolic compound appearing in coffee, honeysuckle, and eucommia that showed their potential as antioxidants and neuroprotectors. In this study, we investigated the anti-PD activity of CGA by testing its effect on 1-methyl-4-phenyl-1-1,2,3,6-tetrahydropyridine (MPTP) zebrafish model of PD. It was shown that CGA relieved MPTP-induced PD-like symptoms including DA neurons and blood vessel loss, locomotion reduction, and apoptosis events in brain. Moreover, CGA modulated the expression of PD- and autophagy-related genes (α-syn, lc3b, p62, atg5, atg7, and ulk1b), showing its ability to promote the autophagy which was interrupted in the PD pathology. The unblocked effect of CGA on autophagy was further verified in 6-hydroxydopamine (6-OHDA)-modeled SHSY5Y cells. Our findings indicated that CGA might relieve PD by boosting the autophagy in neuronal cells that makes CGA a potential candidate for anti-PD treatment.

Pyrrolidinedione-thiazolidinone hybrid molecules with potent cytotoxic effect in squamous cell carcinoma SCC-15 cells

The hybrid heterocyclic molecules are perspective materials in the development of anticancer drugs. Here, the pyrrolidinedione-thiazolidinone hybrid molecules were designed as potent anticancer agents. This study aimed to investigate the cytotoxic effect of three derivatives 1-(4-hydroxyphenyl)-, 1-(4-chlorophenyl)- and 1-(4-bromophenyl)-3-[5-[2-chloro-3-(4-nitrophenyl)prop-2-enylidene]-4-oxo-2-thioxothiazolidine-3-yl]pyrrolidine-2,5-diones (Les-6287, Les-6294, and Les-6328, respectively), their effect on the production of the reactive oxygen species (ROS), apoptosis induction, and expression of genes - PPARγ, AHR, and NRFL2 - whose products are important in metabolism in human tongue squamous cell carcinoma cells of SCC-15 line. The results of resazurin reduction and lactate dehydrogenase (LDH) release assays proved the toxicity of the tested derivatives for the SCC-15 cells. Les-6287, Les-6294, and Les-6328 inhibited the viability of SCC-15 cells with the half-maximal effective concentration (EC50) in the range of 10.18-32.75 µM at 24 and 48 h treatment. These derivatives reduced the metabolism of SCC-15 cells with the half-maximal inhibitory concentration (IC50) of 6.72-39.85 µM at 24 and 48 h treatment. Les-6287, Les-6294, and Les-6328 reduced the metabolism of normal human keratinocytes of HaCaT line murine fibroblasts of Balb/c 3T3 line to a lesser extent. The compounds used in a range from 50 to 100 µM concentrations decreased ROS production in the SCC-15 cells. The derivatives Les-6287 and Les-6328 decreased the level of expression of mRNA of PPARγ, AHR, and NRFL2 genes in these cells at PPARγ siRNA knockdown and without it. Thus, the anticancer effect of studied hybrid pyrrolidinedione-thiazolidinones in the SCC-15 carcinoma cells is accompanied by a reduction of their metabolic activity and ROS level, and increase in caspase 3 activity. However, these changes are not the result of direct interaction of Les-6287, Les-6294, and Les-6328 with the PPARγ molecule.

Isoliquiritigenin induces neurodevelopmental-toxicity and anxiety-like behavior in zebrafish larvae

Isoliquiritigenin, a flavonoid compound, exhibits a variety of pharmacological properties, including anti-inflammatory, anti-oxidative, anti-microbial, anti-viral, and anti-tumor effects. In the past few years, the consumption of isoliquiritigenin-containing dietary supplements has increased due to their health benefits. Although the neuroprotective effects of isoliquiritigenin have been well-investigated, these studies were performed in cells and adult animals. The potential effects of isoliquiritigenin on the development, especially the neurodevelopment, of certain populations, such as zebrafish larvae, have not been investigated. In this study, zebrafish larvae were employed as a model to investigate the effects of isoliquiritigenin on development and neurodevelopment. Zebrafish embryos treated with high concentrations of isoliquiritigenin (10 and 15 μM) exhibited high rates of mortality, hatching, and malformation, indicating that isoliquiritigenin can affect zebrafish development. In addition, isoliquiritigenin impeded the development of central nervous system regions and the length of dopaminergic neurons located in midbrains and thalami of transgenic zebrafish larvae. The locomotor ability of zebrafish larvae exposed to high concentrations of isoliquiritigenin was negatively affected. The total distance and the average velocity significantly decreased, and anxiety-related behaviors were observed under light-dark challenge. Furthermore, the levels of gap43, tuba1b, mbp, hcrt, vmat2, and pomc, which mediate neurodevelopment, neurotoxicity, and anxiety were significantly decreased in zebrafish larvae exposed to isoliquiritigenin. These results indicate that isoliquiritigenin can disrupt the development of dopaminergic neurons and the function of the central nervous system in zebrafish, causing anxiety-like symptoms.

Molecular design, synthesis and anticancer activity of new thiopyrano[2,3-d]thiazoles based on 5-hydroxy-1,4-naphthoquinone (juglone)

A series of 11-substituted 9-hydroxy-3,5,10,11-tetrahydro-2H-benzo[6,7]thiochromeno[2,3-d][1,3]thiazole-2,5,10-triones 3.1-3.13 were synthesized via hetero-Diels-Alder reaction of 5-ene-4-thioxo-2-thiazolidinones and 5-hydroxy-1,4-naphthoquinone (juglone). The structure of newly synthesized compounds was established by means of spectral data and a single-crystal X-ray diffraction analysis. The synthesized compounds were tested on a panel of cell lines representing different types of cancer as well as normal and pseudonormal cells and peripheral human blood lymphocytes. Compound 3.10 was found to be the most active derivative, exhibiting a cytotoxic effect similar to doxorubicin's one (IC₅₀ ranged from 0.6 to 5.98 μM), but less toxic to normal and pseudonormal cells. All synthesized compounds were able to interact with DNA, although their anticancer activity did not correlate with the potency of interaction with DNA. The status of p53 in colorectal cancer cells correlated with the activity of the synthesized derivatives 3.1, 3.7, and 3.10. Compound 3.10 did not have an acute toxic effect on the body of С57BL/6 mice, unlike the well-known anticancer drug doxorubicin, which was used as a positive control. The injection of 3.10 (20 mg/kg) to mice had no effect on the counts of leukocytes, erythrocytes, platelets and hemoglobin level in their blood, in contrast to doxorubicin, which caused anemia and leukopenia, indicating bio-tolerance of 3.10in vivo.

Bioisosteric replacement of 1H-1,2,3-triazole with 1H-tetrazole ring enhances anti-leukemic activity of (5-benzylthiazol-2-yl)benzamides

Previously, we discovered that N-(5-benzyl-1,3-thiazol-2-yl)-4-(5-methyl-1H-1,2,3-triazol-1-yl)benzamide possessed a remarkable cytotoxic effect on 28 cancer cell lines with IC₅₀ < 50 μM, including 9 cancer cell lines, where IC₅₀ was in the range of 2.02-4.70 μM. In the present study, we designed a novel N-(5-benzylthiazol-2-yl)amide compound 3d that was synthesized using the original bioisosteric replacement of 1H-1,2,3-triazole ring by the 1H-tetrazole ring. A significantly enhanced anticancer activity in vitro with an excellent anti-leukemic potency towards chronic myeloid leukemia cells of the K-562 line was demonstrated. Two compounds - 3d and 3l - were highly cytotoxic at nanomolar concentrations towards various tumor cells of the following lines: K-562, NCI-H460, HCT-15, KM12, SW-620, LOX IMVI, M14, UACC-62, CAKI-1, and T47D. As a highlight, the compound N-(5-(4-fluorobenzyl)thiazol-2-yl)-4-(1H-tetrazol-1-yl)benzamide 3d inhibited the growth of leukemia K-562 cells and melanoma UACC-62 cells with IС₅₀ of 56.4 and 56.9 nM (SRB test), respectively. The viability of leukemia K-562 and pseudo-normal HaCaT, NIH-3T3, and J774.2 cells was measured by the MTT assay. Together with SAR analysis, it allowed the selection of a lead compound 3d, which demonstrated the highest selectivity (SI = 101.0) towards treated leukemic cells. The compound 3d caused DNA damage (single-strand breaks detected by the alkaline comet assay) in the leukemic K-562 cells. The morphological study of the K-562 cells treated with compound 3d revealed changes consistent with apoptosis. Thus, the bioisosteric replacement in (5-benzylthiazol-2-yl)amide scaffold proved to be a perspective approach in the design of novel heterocyclic compounds with enhanced anticancer potential.

Elevation of truncated (48 kDa) form of unconventional myosin 1C in blood serum correlates with severe Covid-19

In Covid-19 and autoimmune patients, there are several similarities revealed in the immune responses (Liu et al., 2021; Woodruff et al., 2020). Earlier, we firstly detected a truncated (48 kDa) form of the unconventional Myosin 1C (48/Myo1C) in a fraction of proteins soluble in 10% 2,2,2-trichloroacetic acid (TCA). These proteins were obtained from blood serum of patients with autoimmune diseases, such as multiple sclerosis, systemic lupus erythematosus, and rheumatoid arthritis (Kit et al., 2018). Here, we demonstrated that content of 48/Myo1C was also elevated in blood serum of the severe Covid-19 patients. Whereas in blood of 28 clinically healthy human individuals regularly tested for Covid-19 infection, the amount of this protein was undetectable or very low, in blood of 16 of 28 patients hospitalized with severe course of this disease, its amount was significantly increased. Dexamethasone, steroid hormone which is widely used for treatment of severe Covid-19 patients, induced time-dependent elevation of the 48/Myo1C in blood of such patients. The 48/Myo1C dose-dependently suppressed the viability of anti-CD3-activated lymphocytes of human peripheral blood. Recently, we used affinity chromatography on the magnetic poly(glycidyl-methacrylate) (mag-PGMA-NH₂) microparticles functionalized with Myo1C and MALDI-TOF mass spectrometry with molecular modeling in silico in order to identify potential molecular partners of the 48/Myo1C. It was found that 48/Myo1C might bind to component 3 of the complement system and the anti-thrombin-III (Starykovych et al., 2021). Thus, the mechanisms of the pathogenic action of truncated form of Myo1C in severe COVID-19 patients may involve a suppression of the immune cells, as well as modulation of complement and coagulation cascades.

Potential implications of polyphenolic compounds in neurodegenerative diseases

Neurodegenerative diseases are common chronic diseases related to progressive damage to the nervous system. Current neurodegenerative diseases present difficulties and despite extensive research efforts to develop new disease-modifying therapies, there is still no effective treatment for halting the neurodegenerative process. Polyphenols are biologically active organic compounds abundantly found in various plants. It has been reported that plant-derived dietary polyphenols may improve some disease states and promote health. Emerging pieces of evidence indicate that polyphenols are associated with neurodegenerative diseases. This review aims to overview the potential neuroprotective roles of polyphenols in most common neurodegenerative disorders, including Alzheimer's disease, Parkinson's disease, epilepsy, and ischemic stroke.

Covalent Conjugate of Ser-Pro-Cys Tripeptide with PEGylated Comb-Like Polymer as Novel Killer of Human Tumor Cells

Recently, we detected a previously unknown Ser-Pro-Cys (SPC) tripeptide in the blood serum of multiple sclerosis patients. Its role as a biomarker of the autoimmune disease was suggested, although its origin and real biological activity remained unclear. Here, we created a biocompatible PEGylated comb-like polymer that was used as a platform for covalent immobilization of the SPC, which provided a possibility to explore the biological activity of this tripeptide. This macromolecular conjugate was synthesized via a reaction of the terminal epoxide group of the biocompatible copolymer of dimethyl maleate (DMM) and polyethylene glycol methyl ether methacrylate (PEGMA) with the amino group of the SPC tripeptide. Unexpectedly, the resulting conjugate containing SPC demonstrated anticancer activity in vitro. It possessed pro-apoptotic action toward human tumor cells, while there was no cytotoxic effect of that conjugate toward normal lymphocytes of human peripheral blood. The detected biological effects of the created conjugate inspired us to carry out a thorough study of structural and colloidal-chemical characteristics of this surface-active copolymer containing side PEG chains and a terminal nontoxic synthetic fragment. The copolymer composition, in particular, the content of the peptide fragment, was determined via elemental analysis and NMR spectroscopy. At CMC, it formed polymeric micelle-like structures with a hydrodynamic diameter of 180 ± 60 nm. The conjugation of the peptide fragment to the initial comb-like copolymer caused a change of zeta-potential of the formed micelle-like structures from -0.15 to 0.32 mV. Additional structural modification of the created polymeric nanoplatform was performed via attachment of fluorescein isothiocianate (FITC) dye that permitted monitoring of the behavior of the bioactive SPC-functionalized conjugate in the treated tumor cells. Its penetration into those cells and localization in their cytoplasm were revealed. The principal novelty of this study consists in finding that covalent conjugation of two nontoxic compounds-SPC tripeptide and comb-like PEGylated polymer-led to an unexpected synergy which appeared in the distinct cytotoxic action of the macromolecular complex toward human tumor cells. A potential role of peculiarities of the colloidal-chemical properties of the novel conjugate in its cytotoxic effect are discussed. Thus, synthesized comb-like PEGylated polymers can provide a prospective nanoplatform for drug delivery in anticancer chemotherapy.

1,4-Naphthoquinone Motif in the Synthesis of New Thiopyrano[2,3-d]thiazoles as Potential Biologically Active Compounds

A series of 11-substituted 3,5,10,11-tetrahydro-2H-benzo[6,7]thiochromeno[2,3-d][1,3]thiazole-2,5,10-triones were obtained via hetero-Diels-Alder reaction of 5-alkyl/arylallylidene/-4-thioxo-2-thiazolidinones and 1,4-naphthoquinones. The structures of newly synthesized compounds were established by spectral data and a single-crystal X-ray diffraction analysis. According to U.S. NCI protocols, compounds 3.5 and 3.6 were screened for their anticancer activity; 11-Phenethyl-3,11-dihydro-2H-benzo[6,7]thiochromeno[2,3-d]thiazole-2,5,10-trione (3.6) showed pronounced cytotoxic effect on leukemia (Jurkat, THP-1), epidermoid (KB3-1, KBC-1), and colon (HCT116wt, HCT116 p53-/-) cell lines. The cytotoxic action of 3.6 on p53-deficient colon carcinoma cells was two times weaker than on HCT116wt, and it may be an interesting feature of the mechanism action.

CHITOSAN ADDUCT WITH TRANEXAMIC ACID AND ITS HAEMOSTATIC EFFECT

Chitosan is a cationic polymer capable of binding acidic drugs. In addition, it has haemostatic and antimicrobial activity. Chitosan derivatives withanti-fibrinolytic properties may present increased effectiveness, especially when the added substance forms an adduct with chitosan. The aim of this work was to study the haemostatic action of the chitosan–tranexamic acid complex. Two chitosan solutions (molecularweight of 250 and 625 kDa at pH 5.7 and 6.2, and after tranexamic acid had been added to chitosan solutions) werestudied. Haemostatic evaluation was performed on white outbred mice. The time to complete cessation of bleeding from the tail was determined. Chitosan 625 kDa at pH 6.2 had the best haemostatic properties. Adding tranexamic acid to the chitosan solution reduced the bleeding time. This phenomenon was more pronounced for chitosan 625 kDa. Compared with control animals, this chitosan reduced bleeding arrest time by 30% and the chitosan–tranexamic acid adduct reduced the bleeding arrest time by 75%.

Development of Novel Pyridine-Thiazole Hybrid Molecules as Potential Anticancer Agents

Novel pyridine-thiazole hybrid molecules were synthesized and subjected to physico-chemical characterization and screening of their cytotoxic action towards a panel of cell lines derived from different types of tumors (carcinomas of colon, breast, and lung, glioblastoma and leukemia), and normal human keratinocytes, for comparison. High antiproliferative activity of the 3-(2-fluorophenyl)-1-[4-methyl-2-(pyridin-2-ylamino)-thiazol-5-yl]-propenone 3 and 4-(2-{1-(2-fluorophenyl)-3-[4-methyl-2-(pyridin-2-ylamino)-thiazol-5-yl]-3-oxopropylsulfanyl}-acetylamino)-benzoic acid ethyl ester 4 was revealed. The IC50 of the compound 3 in HL-60 cells of the acute human promyelocytic leukemia was 0.57 µM, while in the pseudo-normal human cell lines, the IC50 of this compound was >50 µM, which suggests that the compounds 3 and 4 might be perspective anticancer agents. The detected selectivity of the derivatives 3 and 4 for cancer cell lines inspired us to study the mechanisms of their cytotoxic action. It was shown that preincubation of tumor cells with Fluzaparib (inhibitor of PARP1) reduced the cytotoxic activity of the derivatives 3 and 4 by more than twice. The ability of these compounds to affect DNA nativity and cause changes in nucleus morphology allows for the suggestion that the mechanism of action of the novel pyridine-thiazole derivatives might be related to inducing the genetic instability in tumor cells.

The voices of Ukrainian and Russian scientists

The brutal attack on Ukraine by the Russian Federation has shocked the world. While the world works to end the violence and help refugees, as a scientific journal, our thoughts are also with those in the scientific community who are directly or indirectly impacted by the war. We have been inspired by and applaud the labs around the world that have opened their doors to displaced scientists and remain committed to supporting scientists, whoever and wherever they are. Because science requires collaboration and trust, we urge the scientific community to continue efforts like this and to remain united, especially in times as difficult as these. In this Voices piece, we feature short comments from scientists from Ukraine and scientists from Russia. This small sampling is far from exhaustive, but our sincere thanks go to those scientists who were willing to share their thoughts on this volatile and emotionally charged situation; the views expressed are those of the contributors alone. We join the world in hoping for a swift resolution to the conflict, for the good of humanity.

Landomycins as glutathione-depleting agents and natural fluorescent probes for cellular Michael adduct-dependent quinone metabolism

Landomycins are angucyclines with promising antineoplastic activity produced by Streptomyces bacteria. The aglycone landomycinone is the distinctive core, while the oligosaccharide chain differs within derivatives. Herein, we report that landomycins spontaneously form Michael adducts with biothiols, including reduced cysteine and glutathione, both cell-free or intracellularly involving the benz[a]anthraquinone moiety of landomycinone. While landomycins generally do not display emissive properties, the respective Michael adducts exerted intense blue fluorescence in a glycosidic chain-dependent manner. This allowed label-free tracking of the short-lived nature of the mono-SH-adduct followed by oxygen-dependent evolution with addition of another SH-group. Accordingly, hypoxia distinctly stabilized the fluorescent mono-adduct. While extracellular adduct formation completely blocked the cytotoxic activity of landomycins, intracellularly it led to massively decreased reduced glutathione levels. Accordingly, landomycin E strongly synergized with glutathione-depleting agents like menadione but exerted reduced activity under hypoxia. Summarizing, landomycins represent natural glutathione-depleting agents and fluorescence probes for intracellular anthraquinone-based angucycline metabolism.

Synthesis of novel indole-thiazolidinone hybrid structures as promising scaffold with anticancer potential

A series of novel indole-azolidinone hybrids has been synthesized via Knoevenagel reaction of 5-fluoro-3-formyl-1H-indole-2-carboxylic acid methyl ester and some azolidinones differing in heteroatoms in positions 1, 2 and 4. Their anticancer activity in vitro was screened towards MCF-7 (breast cancer), HCT116 (colon cancer), HepG2 (hepatoma), HeLa (cervical cancer), A549 (lung cancer), WM793 (melanoma) and THP-1 (leukemia) cell lines, and a highly active 5-fluoro-3-(4-oxo-2-thioxothiazolidin-5-ylidenemethyl)-1H-indole-2-carboxylic acid methyl ester (3a) was identified and subjected to in-depth investigation of cytotoxicity mechanisms. This compound was found to possess the highest cytotoxic action towards tumor cells comparing with the action of other derivatives (1, 3b, 3c, 3d, 3e). Compound 3a exhibited toxicity toward MCF-7, HCT116, and A549, HepG2 cancer cells, while the non-malignant cells (human keratinocytes of HaCaT line and murine embryonic fibroblasts of Balb/c 3T3 line) possessed moderate sensitivity to it. The compound 3a induced apoptosis in studied tumor cells via caspase 3-, PARP1-, and Bax-dependent mechanisms; however, it did not affect the G1/S transition in HepG2 cells. The compound 3a impaired nuclear DNA in HepG2, HCT116, and MCF-7 cells without intercalating this biomolecule, but much less DNA damage events were induced by 3a in normal Balb/c 3T3 fibroblasts compared with HepG2 carcinoma cells. Thus, 5-fluoro-3-(4-oxo-2-thioxothiazolidin-5-ylidenemethyl)-1H-indole-2-carboxylic acid methyl ester 3a was shown to trigger DNA damage and induce apoptosis of human tumor cells and it might be considered as an anticancer agent perspective for in-depth studies.

Treatment of Parkinson's disease in Zebrafish model with a berberine derivative capable of crossing blood brain barrier, targeting mitochondria, and convenient for bioimaging experiments

Berberine is a famous alkaloid extracted from Berberis plants and has been widely used as medications and functional food additives. Recent studies reveal that berberine exhibits neuroprotective activity in animal models of Parkinson's disease (PD), the second most prevalent neurodegenerative disorders all over the world. However, the actual site of anti-PD action of berberine remains largely unknown. To this end, we employed a fluorescently labeled berberine derivative BBRP to investigate the subcellular localization and blood brain barrier (BBB) permeability in a cellular model of PD and zebrafish PD model. Biological investigations revealed that BBRP retained the neuroprotective activity of berberine against PD-like symptoms in PC12 cells and zebrafish, such as protecting 6-OHDA induced cell death, relieving MPTP induced PD-like behavior and increasing dopaminergic neuron loss in zebrafish. We also found that BBRP could readily penetrate BBB and function in the brain of zebrafish suffering from PD. Subcellular localization study indicated that BBRP could rapidly and specifically accumulate in mitochondria of PC12 cells when it exerted anti-PD effect. In addition, BBRP could suppress accumulation of Pink1 protein and inhibit the overexpression of LC3 protein in 6-OHDA damaged cells. All these results suggested that the potential site of action of berberine is mitochondria in the brain under the PD condition. Therefore, the findings described herein would be useful for further development of berberine as an anti-PD drug.

Synthesis of disaccharide modified berberine derivatives and their anti-diabetic investigation in zebrafish using a fluorescence-based technology

Berberine is a naturally occurring isoquinoline alkaloid and has been used as an important functional food additive in China due to its various pharmacological activities. Berberine exhibits great potential for developing anti-diabetic agents against type 2 diabetes mellitus (T2DM), as it can reduce the blood glucose level in many animal models. However, the low anti-diabetic activity and poor bioavailability of berberine (below 5%) by oral administration significantly limit its practical applications. To solve these problems, this article focuses on the structural modification of berberine using some disaccharide groups, because the carbohydrate moiety has been proved to improve the bioavailability and enhance the receptor-binding affinity of drugs. Anti-diabetic investigation of the synthesized compounds was performed in a zebrafish model using a fluorescently labelled glucose analog 2-deoxy-2-[(7-nitro-2,1,3-benzoxadiazol-4-yl)amino]-d-glucose (2-NBDG) as a glucose tracker. The results indicated that the modification of berberine with carbohydrate groups could give derivatives with improved anti-diabetic activity, in particular the diglucose modified berberine derivative 1 which could dramatically promote the uptake of 2-NBDG in both zebrafish larvae and their eyes even at very low concentrations. Furthermore, the fluorescence-based anti-diabetic investigation method in zebrafish shows great potential for anti-diabetic drug screening.

Suppression of systemic inflammation and signs of acute and chronic cholangitis by multi-kinase inhibitor 1-(4-Cl-benzyl)-3-chloro-4-(CF3-phenylamino)-1H-pyrrole-2,5-dione

An aberrant activity of growth factor receptors followed by excessive cell proliferation plays a significant role in pathogenesis of cholangitis. Therefore, inhibition of these processes could be a fruitful therapeutic strategy. The effects of multi-kinase inhibitor 1-(4-Cl-benzyl)-3-chloro-4-(CF3-phenylamino)-1H-pyrrole-2,5-dione (MI-1) on the hepatic and systemic manifestations of acute and chronic cholangitis in rats were addressed. MI-1 (2.7 mg/kg per day) was applied to male rats that experienced α-naphthylisothiocyanate-induced acute (3 days) or chronic (28 days) cholangitis. Liver autopsy samples, blood serum markers, and leukograms were studied. MI-1 localization in liver cells and its impact on viability of HepG2 (human hepatoma), HL60 (human leukemia), and NIH3T3 (normal murine fibroblasts) cell lines and lymphocytes of human peripheral blood (MTT, DNA fragmentation, DNA comet assays, Propidium Iodide staining) were assessed. Under both acute and chronic cholangitis, MI-1 substantially reduced liver injury, fibrosis, and inflammatory scores (by 46-86%) and normalized blood serum markers and leukograms. Moreover, these effects were preserved after a 28-day recovery period (without any treatment). MI-1 inhibited the HL60, HepG2 cells, and human lymphocytes viability (IC₅₀ 0.6, 9.5 and 8.3 µg/ml, respectively), while NIH3T3 cells were resistant to that. Additionally, HepG2 cells and lymphocytes being incubated with MI-1 demonstrated insignificant pro-apoptotic and pro-necrotic changes and DNA single-strand breaks, suggesting that MI-1 effects in liver might be partly caused by its cytotoxic action towards liver cells and lymphocytes. In conclusion, MI-1 attenuated the systemic inflammation and signs of acute and chronic cholangitis partly through cytotoxicity towards cells of hepatic and leukocytic origin.

Isolation and identification in human blood serum of the proteins possessing the ability to bind with 48 kDa form of unconventional myosin 1c and their possible diagnostic and prognostic value

We firstly identified 48 kDa molecular form of the unconventional myosin 1c (p48/Myo1C), and isolated it from blood serum of multiple sclerosis patients. The amount of p48/Myo1C in human blood serum correlated with some autoimmune, hemato-oncological and neurodegenerative diseases and thus may serve as a potential molecular biomarker. The biological functions of this protein in human blood remain unknown. Previously, we used the monodisperse magnetic poly (glycidyl methacrylate)(mag-PGMA-NH₂ ) microspheres with immobilized 48/Myo1C and western-blot analysis, which allowed us to identify IgM and IgG immunoglobulins presenting an affinity to this protein. Here, we used mass spectrometry followed by the western blotting in order to identify other blood serum proteins with affinity to 48/Myo1C. The obtained data demonstrate that 48/Myo1C binds to component 3 of the complement and the antithrombin-III proteins. A combination of magnetic microparticle-based affinity chromatography with MALDI-TOF mass spectrometry and an in silico analysis provided an opportunity to identify the partners of interaction of 48/Myo1C with other proteins, in particular those participating in complement and coagulation cascades.

Magnetic Temperature-Sensitive Solid-Lipid Particles for Targeting and Killing Tumor Cells

Magnetic and temperature-sensitive solid lipid particles (mag. SLPs) were prepared in the presence of oleic acid-coated iron oxide (IO-OA) nanoparticles with 1-tetradecanol and poly(ethylene oxide)-block-poly(ε-caprolactone) as lipid and stabilizing surfactant-like agents, respectively. The particles, typically ~850 nm in hydrodynamic size, showed heat dissipation under the applied alternating magnetic field. Cytotoxic activity of the mag.SLPs, non-magnetic SLPs, and iron oxide nanoparticles was compared concerning the mammalian cancer cell lines and their drug-resistant counterparts using trypan blue exclusion test and MTT assay. The mag.SLPs exhibited dose-dependent cytotoxicity against human leukemia cell lines growing in suspension (Jurkat and HL-60/wt), as well as the doxorubicin (Dox)- and vincristine-resistant HL-60 sublines. The mag.SLPs showed higher cytotoxicity toward drug-resistant sublines as compared to Dox. The human glioblastoma cell line U251 growing in a monolayer culture was also sensitive to mag.SLPs cytotoxicity. Staining of U251 cells with the fluorescent dyes Hoechst 33342 and propidium iodide (PI) revealed that mag.SLPs treatment resulted in an increased number of cells with condensed chromatin and/or fragmented nuclei as well as with blebbing of the plasma membranes. While the Hoechst 33342 staining of cell suggested the pro-apoptotic activity of the particles, the PI staining indicated the pro-necrotic changes in the target cells. These conclusions were confirmed by Western blot analysis of apoptosis-related proteins, study of DNA fragmentation (DNA laddering due to the inter-nucleosomal cleavage and DNA comets due to single strand breaks), as well as by FACS analysis of the patterns of cell cycle distribution (pre-G1 phase) and Annexin V/PI staining of the treated Jurkat cells. The induction of apoptosis or necrosis by the particles used to treat Jurkat cells depended on the dose of the particles. Production of the reactive oxygen species (ROS) was proposed as a potential mechanism of mag.SLPs-induced cytotoxicity. Accordingly, hydrogen peroxide and superoxide radical levels in mag.SLPs-treated Jurkat leukemic cells were increased by ~20–40 and ~70%, respectively. In contrast, the non-magnetic SLPs and neat iron oxides did not influence ROS levels significantly. Thus, the developed mag.SLPs can be used for effective killing of human tumor cells, including drug-resistant ones.

Synthesis of hydrophobically modified berberine derivatives with high anticancer activity through modulation of the MAPK pathway

Linoleic acid-modified berberine derivative induces apoptosis of A549 cells and affects the expression of proteins associated with the MAPK pathway.

The purification and identification of human blood serum proteins with affinity to the antitumor active RL2 lactaptin using magnetic microparticles

The cytopoxic effect of RL2 lactaptin (the recombinant analog of proteolytic fragment of human kappa-casein) toward tumor cells in vitro and in vivo presents it as a novel promising antitumor drug. The binding of any drug with serum proteins can affect their activity, distribution, rate of excretion and toxicity in the human body. Here, we studied the ability of RL2 to bind to various blood serum proteins. Using magnetic microparticles bearing by RL2 as an affinity matrix, in combination with mass spectrometry and western blot analysis, we found a number of blood serum proteins possessing affinity for RL2. Among them IgA, IgM and IgG subclasses of immunoglobulins, apolipoprotein A1 and various cortactin isoforms were identified. This data suggests that in the bloodstream RL2 lactaptin takes part in complicate protein-protein interactions, which can affect its activity.

Enhanced Proapoptotic Effects of Water Dispersed Complexes of 4-Thiazolidinone-Based Chemotherapeutics with a PEG-Containing Polymeric Nanocarrier

AIM

To study whether water formulation of the complex of 4-thiazolidinone derivatives with a PEG-containing polymeric nanocarrier enhances their pro-apoptotic action towards rat glioma C6 cells.

METHODS

Mechanisms of antineoplastic effects of 4-thiazolidinone derivatives were investigated in vitro with rat glioma C6 cells. Cell nativity, cell cycling pattern, and Annexin V expression were evaluated and DNA damage was estimated by DNA comet analysis. A novel water-based formulation of 4-thiazolidinone derivatives complexed with a polymeric nanocarrier was utilized for enhancing pro-apoptotic action towards C6 cells.

RESULTS

The studied 4-thiazolidinone derivatives use apoptosis mechanisms for killing rat glioma C6 cells, as confirmed by FACS analysis of these cells in pre-G1 stage, the appearance of Annexin V positive C6 cells, and an increased number of DNA comets of higher classes. Complexation of the studied compounds with a PEG-containing polymeric nanocarrier significantly increased pro-apoptotic effects in rat glioma C6 cells measured by all methods mentioned above.

CONCLUSION

Complexation of 4-thiazolidinone derivatives with a PEG-containing polymeric nanocarrier provided them with water solubility and enhanced pro-apoptotic effects in rat glioma C6 cells.

Comb-like PEG-containing polymeric composition as low toxic drug nanocarrier

BACKGROUND

Development of biocompatible multifunctional polymeric drug carriers is crucial in modern pharmaceutics aimed to create "smart" drugs. The high potential of the PEGylated comb-like polymeric nanocarrier (PNC) in delivering both traditional and experimental drugs to tumor cells in vitro and in vivo has been demonstrated previously. In the present study, we investigated the general toxicity of polyethylene glycol (PEG) processed with both covalent and non-covalent attachments of PEG to compose a comb-like polymer that behaves like a simple chain of n monomers decorated with swollen side chains. The PNC possesses properties of a water-soluble surfactant containing methyl-terminated PEG side branches in some monomer units attached covalently to the carbon chain backbone.

RESULTS

We have demonstrated that the synthesized PNC possesses weak toxic effects toward human leukemia cells (HL-60 and Jurkat lines), as well as toward hepatocellular (HepG2), colon (HCT116) and breast (MCF-7) tumor cell lines. Additionally, after a long period (20 days) of intraperitoneal administration, the PNC had no significant toxic effects in laboratory white mice (470 mg/kg body mass in 1 ml) and Wistar rats (440 mg/kg body mass in 10 ml).

CONCLUSION

The developed PNC we studied can be qualified as a compound of grade 4 toxicity (low toxicity substance). The reduced toxicity of this PNC in combination with its improved bioavailability and previously detected capability to enhance cytotoxicity toward tumor cells in vitro and potential tumor treatment effects in vivo suggests its potential as a safe drug delivery platform for treating various diseases, especially cancer.

Monodisperse magnetic poly(glycidyl methacrylate) microspheres for isolation of autoantibodies with affinity for the 46 kDa form of unconventional Myo1C present in autoimmune patients

Monodisperse nonmagnetic macroporous poly(glycidyl methacrylate) (PGMA) microspheres were synthesized by multistep swelling polymerization of glycidyl methacrylate, ethylene dimethacrylate and 2-[(methoxycarbonyl)methoxy]ethyl methacrylate (MCMEMA). This was followed (a) by ammonolysis to modify the microspheres with amino groups, and (b) by incorporation of iron oxide (γ-Fe₂O₃) into the pores to render the particles magnetic. The resulting porous and magnetic microspheres were characterized by scanning and transmission electron microscopy (SEM and TEM), atomic absorption and Fourier transform infrared spectroscopy (AAS and FTIR), elemental analysis, vibrating magnetometry, mercury porosimetry and Brunauer-Emmett-Teller adsorption/desorption isotherms. The microspheres are meso- and macroporous, typically 5 μm in diameter, contain 0.9 mM · g^-1 of amino groups and 14 wt.% of iron according to elemental analysis and AAS, respectively. The particles were conjugated to p46/Myo1C protein, a potential biomarker of autoimmune diseases, to isolate specific autoantibodies in the blood of patients suffering from multiple sclerosis (MS). The p46/Myo1C loaded microspheres are shown to enable the preconcentration of minute quantities of specific immunoglobulins prior to their quantification via SDS-PAGE. The immunoglobulin M (IgM) with affinity to Myo1C was detected in MS patients. Graphical abstract Monodisperse magnetic poly(glycidyl methacrylate) microspheres were synthesized, conjugated with 46 kDa form of unconventional Myo1C protein (p46/Myo1C) via carbodiimide (DIC) chemistry, and specific autoantibodies isolated from blood of multiple sclerosis (MS) patients; immunoglobulin M (IgM) level increased in MS patients.

4-Thiazolidinone derivative Les-3833 effectively inhibits viability of human melanoma cells through activating apoptotic mechanisms

Aim

To evaluate cytotoxic action of 4-thiazolidinone derivative Les-3833 and study the mechanisms of its pro-apoptotic action toward human melanoma cells and human tumor cell lines of other tissue origin.

Methods

The effect of Les-3833 or doxorubicin on the viability of 9 cell lines was studied using MTT assay, while human melanoma cells of WM793 line were additionally examined using light and fluorescent microscopies for evaluating cytomorphological changes. The Western-blot and flow cytometric analyses were carried out to study signaling pathways of melanoma cell cycling and death.

Results

Les-3833 was the most efficient against melanoma cells. Its half maximal inhibitory concentration (IC₅₀) was 0.22 μg/mL for WM793 cells and 0.3 μg/mL for SK-Mel-28 melanoma cells. For human lung A549, breast MCF-7, colon HCT116, and ovarian SKOV3 carcinoma cell lines IC₅₀ was in between 2.5 to >5.0 μg/mL. Les-3833 was relatively not toxic (IC₅₀ ˃ 5 μg/mL) for human embryonic kidney HEK293 cells. Results of Annexin V/PI staining of melanoma cells and activation of caspase 3, PARP, MAPK, and EndoG protein suggest apoptosis in Les-3833-treated cells. Les-3833 also induced ROS production in melanoma cells and their arrest in G₀/G₁ phase of cell cycle.

Conclusion

Novel 4-thiazolidinone derivative Les-3833 is effective against human melanoma cells in vitro, and such effect is tumor specific since it is much less pronounced in human carcinoma and leukemia cells. In melanoma cells Les-3833 induces apoptosis (morphological changes and increased pro-apoptotic proteins), ROS production, and arrest in G₀/G₁ phase of cell cycle.

Anti-histone H1 IgGs possess proliferative activity towards human T-leukaemia CEM cells

The aim of this study was to characterize the proliferative activity of the anti-histone H1 IgGs towards human T-leukaemia CEM cells.

MATERIALS AND METHODS

Anti-histone H1 IgGs were purified from blood serum of systemic lupus erythematosus patients by precipitation of serum proteins with 50% ammonium sulfate followed by a sequential affinity chromatography on Protein G-Sepharose and histone H1-Sepharose columns. To avoid contamination with other proteins, anti-histone H1 IgGs were subjected to strongly acidic pH 2.0 during gel filtration through HPLC column. The effects of the anti-histone H1 IgGs on cell viability and cell cycle were tested by MTS-assay and flow cytometry, correspondingly. The cross-reactivity of the anti-histone H1 antibodies towards heterogenetic and cellular antigens was evaluated by Western-blot analysis.

RESULTS

It was found that incubation of CEM cells with the HPLC-purified anti-histone H1 IgGs resulted in significant stimulation of cell growth by 46% after 48 h of incubation. These IgGs possess an antigenic poly-specificity to positively charged heterogenetic antigens and different cellular antigens. FITC-labeled and biotinylated anti-histone H1 IgGs are internalized by CEM cells and preferentially accumulated in the cytoplasm.

CONCLUSION

The anti-histone H1 IgGs are shown to internalize human T-leukemia CEM and stimulate their proliferation. These IgGs are polyspecific toward cellular antigens.

Interleukin 6/Wnt interactions in rheumatoid arthritis: interleukin 6 inhibits Wnt signaling in synovial fibroblasts and osteoblasts

Aim

To evaluate the impact of previously unrecognized negative interaction between the Wnt and interleukin (IL) 6 signaling pathways in skeletal tissues as a possible major mechanism leading to age- and inflammation-related destruction of bone and joints.

Methods

Luciferase reporter assays were performed to monitor Wnt pathway activation upon IL-6 and tumor necrosis factor-α (TNFα) treatment. Functional contribution of IL-6 and TNFα interaction to inhibition of bone formation was evaluated in vitro using small hairpin RNAs (shRNA) in mouse mesenchymal precursor cells (MPC) of C2C12 and KS483 lines induced to differentiate into osteoblasts by bone morphogenetic proteins (BMP).

Results

IL-6 inhibited the activation of Wnt signaling in primary human synoviocytes, and, together with TNFα and Dickkopf-1, inhibited the activation of Wnt response. ShRNA-mediated knockdown of IL-6 mRNA significantly increased early BMP2/7-induced osteogenesis and rescued it from the negative effect of TNFα in C2C12 cells, as well as intensified bone matrix mineralization in KS483 cells.

Conclusion

IL-6 is an important mediator in the inhibition of osteoblast differentiation by TNFα, and knockdown of IL-6 partially rescues osteogenesis from the negative control of inflammation. The anti-osteoblastic effects of IL-6 are most likely mediated by its negative interaction with Wnt signaling pathway.

Compositions of Anticancer Drug with Micellar Nanocarriers and Their Cytotoxicity

Asymmetric diblock (DBC) and triblock (TBC) copolymers contained biocompatible chemically complementary polyacrylamide and poly(ethylene oxide) (PAAm-b-PEO-b-PAAm) or its monomethyl ether (MEPEO-b-PAAm), and also partially hydrolyzed triblock copolymer derivative (TBChydr) were used to create micelles of a special type. The micelles obtained are characterized by small CMCs and large values of the Gibbs micellization energy, thus indicating a high stability of DBC, TBC and TBChydr micelles in aqueous solutions and the capabilities of their use to encapsulate and deliver poorly soluble and/or toxic drugs in living organism. Morphological features and size of DBC and TBC micelles were determined by TEM. The electron images demonstrated spherical micelles of a polymolecular type, monomolecular type and separate micelle aggregates. TBC and TBChydr micelles were used to examine in vitro anticancer activity of their compositions with doxorubicin (Dox). The created micelle systems showed the enhanced cytotoxicity as compared to individual Dox against murine leukemia cells of L1210 line, murine transformed fibroblasts of L929 line and human T-leukemia cells of Jurkat line and allow to achieve a high efficacy at low Dox concentrations (0,1÷3 µg·cm-3) that opens the great prospects for essential decrease in drug dose at chemotherapy.

Identification of SER-PRO-CYS Peptide in Blood Serum of Multiple Sclerosis Patients

Monitoring of multiple sclerosis (MS) requires additional molecular markers. Recently, we used original TCA-precipitation/extraction approach in combination with MALDI TOF/TOF mass-spectrometry and identified earlier unknown 48 kDa form of the unconventional myosin IC isoform b (Myo1C) in blood serum of the MS patients. Further examination of TCA-extracted fraction of blood serum of these patients by means of thin-layer chromatography and HPLC gel-filtration allowed detecting 300-500 Da peptides. MALDI TOF/TOF massspectrometry of these peptides showed that they contain Ser-Pro-Cys amino acid sequence. We discussed potential mechanisms of a release of these peptides that were earlier unknown in blood serum of the MS patients.

Identification of a 48 kDa form of unconventional myosin 1c in blood serum of patients with autoimmune diseases

We searched for protein markers present in blood serum of multiple sclerosis (MS), rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE) patients in comparison to healthy human individuals. We used precipitation/extraction methods and MALDI TOF/TOF mass spectrometry, and identified a protein with Mr ~46 kDa as a fragment of human unconventional myosin IC isoform b (Myo1C). Western blotting with specific anti-human Myo1C antibodies confirmed the identity. Screening of blood serum samples from different autoimmune patients for the presence of Myo1c revealed its high level in MS and RA patients, relatively low level in SLE patients, and undetected in healthy donors. These data are suggesting that the level of p46 Myo1C in blood serum is a potential marker for testing of autoimmune diseases.

Hepatic metallothioneins in molecular responses to cobalt, zinc, and their nanoscale polymeric composites in frog Rana ridibunda

Despite numerous studies suggesting a dramatic decline of amphibians, the biochemical mechanisms of adaptation in these animals to polluted environment are poorly studied. The aim of this study was to elucidate the ability to release cobalt (Co) and zinc (Zn) from their nanoscale complexes (NCs) derived from the polymeric substance of N-vinylpyrrolidone (PS) in the liver of amphibian (Rana ridibunda). Frog males were subjected to 14days exposure to waterborne Co(2+) (50μg/L), Zn(2+) (100μg/L), as well as corresponding concentrations of Co-NC, Zn-NC or PS. Main attention was paid to MT's interrelations with indices of stress and toxicity. Only Co(2+) and Zn(2+) caused elevation of the correspondent metal in MTs. Co(2+) caused down-regulation of cathepsin D activity, while Zn(2+), Zn-NC and the PS up-regulated this activity. Zn(2+) provoked 1.6 times increase of metal-bounded form of the MT (MT-Me), while all other exposures caused the elevation of the ratio of MT total protein concentration (MT-SH) and concentrations of the MT-Me and/or immunoreactive (MTi) form (up to ~10 times) accompanied by a decrease in the levels of oxyradicals. The increased DNA fragmentation and down-regulation of caspase-3 activity in relation to the redox state of glutathione and/or lactate/pyruvate were shown at all exposures. These data indicate the vulnerability of the redox state of cellular thiols and inability to release Co and Zn from NCs in frog's liver.

Use of specific polysaccharide-immobilized monodisperse poly(glycidyl methacrylate) core-silica shell microspheres for affinity purification of lectins

Immobilization of polysaccharides (yeast mannan and gum arabic) on the macroporous poly(glycidyl methacrylate) monodisperse microspheres coated with silica (SiO2 )-containing amino groups on the surface was used to prepare affinity sorbents for lectin purification. The efficiency of isolating mannose specific Pisum sativum lectin was demonstrated on sorbent with immobilized yeast mannan and that of galactose specific Glycine hispida lectin on sorbent with immobilized gum arabic. The microspheres with immobilized polysaccharides can be used for selecting an affinity sorbent for purification of other mannose- and galactose-specific lectins. In contrast to yeast mannan, the gum arabic immobilized on the microspheres possesses much narrower specificity and is suitable for purification of only those galactose specific lectins which interact well with l-rhamnose or l-arabinose. The synthesized macroporous particles are capable of immobilizing 50 mg of polysaccharide per 1 g of the matrix, which is 10 times higher than the capacity of epoxy-activated Sepharose 6B. That makes it possible to obtain the same lectin quantity using a column of 10 times smaller volume. Another advantage of novel affinity sorbents comparing corresponding Sepharose gels is the possibility of sorbent drying after use.

Desialylation of dying cells with catalytically active antibodies possessing sialidase activity facilitate their clearance by human macrophages

Recently we reported the first known incidence of antibodies possessing catalytic sialidase activity (sialidase abzymes) in the serum of patients with multiple myeloma and systemic lupus erythematosus (SLE). These antibodies desialylate biomolecules, such as glycoproteins, gangliosides and red blood cells. Desialylation of dying cells was demonstrated to facilitate apoptotic cell clearance. In this study we assessed the possibility to facilitate dying cell clearance with the use of F(ab)2 fragments of sialidase abzymes. Two sources of sialidase abzymes were used: (i) those isolated from sera of patients with SLE after preliminary screening of a cohort of patients for sialidase activity; and (ii) by creating an induced sialidase abzyme through immunization of a rabbit with synthetic hapten consisting of a non-hydrolysable analogue of sialidase reaction conjugated with bovine serum albumin (BSA) or keyhole limpet haemocyanin (KLH). Antibodies were purified by ammonium sulphate precipitation, protein-G affinity chromatography and size exclusion-high performance liquid chromatography (HPLC-SEC). Effect of desialylation on efferocytosis was studied using human polymorphonuclear leucocytes (PMN), both viable and aged, as prey, and human monocyte-derived macrophages (MoMa). Treatment of apoptotic and viable prey with both disease-associated (purified from blood serum of SLE patients) and immunization-induced (obtained by immunization of rabbits) sialidase abzymes, its F(ab)2 fragment and bacterial neuraminidase (as positive control) have significantly enhanced the clearance of prey by macrophages. We conclude that sialidase abzyme can serve as a protective agent in autoimmune patients and that artificial abzymes may be of potential therapeutic value.